By extrusion, ice substance is soft and formable, e.g. at a temperature of -5.degree., and, for ensuring a real separation between the extruded bodies by the cutting of the extruded string, the extruded string should be further frozen before the cutting takes place. It is a usual practice, therefore, that an ice sausage string, or preferably a number of parallel ice strings, be extruded onto a conveyor belt which brings the string through a first freezing zone, in which the ice material is frozen to a `medium low` temperature by which the material is reasonably stiff or self carrying, yet still easily cuttable, whereafter the string is conveyed through a cutting station for being cut into single bodies, which, on the same or a further conveyor, are brought through a following freezing zone in which they are hard frozen. Such a final freezing will often be effected in a special freezing store after packaging or wrapping of the bodies, but if the bodies prior to the packing should be coated with some coating material from a liquid state thereof, then the bodies should be hard frozen prior to such coating being effected, e.g. by dipping of the bodies in a bath of the coating material, as this material will be `warm` relative to the ice material. Particularly where it is required for this reason to hard freeze the bodies prior to a possible packaging or wrapping and thus prior to their transfer to a freezing store the basically simple extrusion process will be less simple, because normally use should be made of two different freezing tunnel units and an intermediate cutting station.